AZD4547 + fulvestrant

AZD4547 + fulvestrant is an investigational combination therapy comprising AZD4547, a potent and selective small molecule inhibitor of fibroblast growth factor receptor (FGFR) 1, 2, and 3 tyrosine kinases, and fulvestrant, a selective estrogen receptor degrader (SERD). This combination is being studied primarily for the treatment of estrogen receptor-positive (ER+) breast cancer patients with FGFR1 polysomy or gene amplification who have progressed following prior endocrine therapy. The rationale for this combination stems from evidence that FGFR pathway activation can drive resistance to endocrine therapies in ER+ breast cancer. By inhibiting both the FGFR signaling pathway with AZD4547 and targeting estrogen receptor signaling with fulvestrant, this regimen aims to overcome resistance mechanisms and improve clinical outcomes in this patient population[1][2][9].